Crankcase scavenger



Jan. 1, 1952 c. c. RANDALL 2,580,594

CRANKCASE SCAVENGER Filed June 6, 1947 2 SHEETS-SHEET l 25' 8 7 2 V o IT] 5 o :IPG 2 IO FIG I 9 2/ INVENTOR. CLARK 0. NBA LL ATT'YS Jan. 1,1952 c. c. RANDALL CRANKCASE SCAVENGER 2 SHEETS-SHEET 2 Filed June 6,1947 FIG.4

F INVENTOR.

22 CLARK QRQNDALL @Mi w-M ATT'YS Patented Jan. 1, 1952 UNITED STATESPATENT OFFICE 3 Claims.

This invention is directed to new and useful improvements in crankcasescavengers whereby the crankcase of an internal combustion automotiveengine is thoroughly and eflicient ventilated of all undesirable fumes,gases and vapors produced during the operation of such engine.

The inventions disclosed herein are modifications, refinements andimprovements on the crankcase scavenger described in my United StatesLetters Patent No. 2,406,103 dated August 20, 1946. While utilizing thesame basic idea of creating the pressure necessary to produce the vacuumto exhaust the fumes from the crankcase by use of the flywheel teethcertain important changes in construction of the parts will be noted.

The primary object of this invention is to provide an efiicientcrankcase scavenger or ventilator that will produce the necessarycombination of high volume of removal at low velocity.

Another object of this invention is to provide a crankcase scavengerwhereby increased pressure is obtained from the flywheel teeth anddirected to an improved aspirator or Venturi attachment whereby anincreased volume of undesirable crankcase fumes are removed from thecrankcase.

Still a further object of the invention is to provide such a devicewherein there is provided adequate means for preventing the removal ofdesirable liquid lubricants from the crankcase during the operation ofthe scavenger.

A still further object is to provide in a crankcase scavenger animproved aspirator attachment.

Another object of the invention is in provide an improved, eflicientairscoop for obtaining pres sure from the flywheel teeth.

And yet another object of the invention is to provide in a scavenger ofthis type a baflle means for preventing liquid lubricants of thecrankcase from being removed by the scavenger from the crankcase.

A further object of this invention is to provide in such a scavenger anovel separator or trap whereby any liquids that may have entered thescavenger from the crankcase will be separated from the undesirablefumes and be returned to the crankcase to continue their lubricatingfunction.

Other objects and advantages will become apparent iromian examination ofthe following detailed specification:

In the drawings:

Fig. 1 is aside elevational view of an internal the improved crankcasescavenger embodying the inventions hereof.

Fig. 2 is a sectional view taken along line 2-2 of Fig. 1 showing theassembly of the airscoop with relation to the flywheel.

Fig. 3 is a perspective view of the improved airscoop attachment.

Fig. 4 is.a vertical sectional view of the new aspirator or Venturiattachment.

Fig. 5 is an enlarged side elevational view of the separator and baflieassembly.

Fig. 6 is an enlarged side elevational view of the bailie attachment.

Fig. '7 is an enlarged end view of the baflle and separator assembly.

In detail, the engine block is indicated by reference character I, thecrankcase 2 and the flywheel casing 3. The usual air inlet to thecrankcase is shown at 4 and an outlet from the crankcase is provided at5.

Connected on the inside of the crankcase at outlet 5 is a baffle member6 and connected to the outlet 5 outside of the crankcase is liquid andgas separator or trap 1. A conduit 8 leads from separator I to Venturior aspirator attachment 9. An airscoop I0 is secured to the flywheelcasing 3 below and ad acent the flywheel ll, an appropriate openinghaving been cut in the bottom of the flywheel casing. A conduit I2connects the airscoop Hi to Venturi 9 to complete the general assemblyof the scavenger.

In detail, the bafiie assembly 6 comprises two spaced plates 13 and I4secured together :at their tops. The sides of the plates are spaced fromeach other to form vertical slots l5 and the lower edge of plate i3 isbentoutwardly to form a lip H5. The outer plate [4 is of less heightthan the inner plate I 3. Plate l4 has a central aperture I4 that alignswith the outlet 5 of the crankcase. Thus is formed a protected exit fromthe crankcase being in fact only a slot extending around the sides andbottoms of the two plates, the access to the bottom being furtherprotected by lip it of inner plate l3. Bolts I! are secured to the upperedges of the plates l3 and I4 and extend outwardly to form means forsecuring the baffle assembly to the inner side of the crankcase. Thebaflle thus formed is in fact a casing with a slot entrance at itsbottom and an outlet in one side. A fitting I8 is positioned oppositethe baflle on the outside of the crankcase wall l9 and is securedthereto, with a gasket 20 in between by means of bolt-2| and nut 22 andby means of nuts 23 tightened onto bolts l'l.

A conduit 26 is clamped to fitting I8 and leads to the bottom ofseparator i. Separator assembly 1 comprises a tubular receiving chamber25 horizontally disposed and provided with a removal cap 25'. The outletfrom chamber 25 is a tube 25 that extends'from a point outside and belowthe chamber 25 through the lower wall of chamber 25 to a pointsubstantially above the floor of the chamber. Thus the separator isprovided with an inlet 21 at the bottom of receiving chamber 25 and anoutlet 28 substantially above the bottom of chamber 25. The removablecap 25 is held in closed position by nut 29 threaded on bolt 30 that issecured to brace 3| that extends across the end of chamber 25.

The conduit 8 leads from the outlet tube 26 to the tube e2 of aspirators. Aspirator 9 has.

a crankcase or fumes inlet 33 and an airscoop or air pressure inlet 34and one outlet passage 35. Tube 32 extends well below side inlet 34 asis usual in this type of aspirator. An outer tubuar casing 38 forms themain body'of the aspirator, surrounds tube 32 and extends well below itslower end. Within'outlet passage 35 and spaced from its outer end andsurrounding the outlet end of tube 32 is a restricting fitting 3? thathas its inlet substantially the diameter of casing 33 and its loweroutlet end 38 of less diameter than casing 36 but of greater diameterthan tube 32. Thus the passageway from air inlet 3 to the outlet 35 isrestricted adjacent the outlet of tube 32 but increases in areathereafter until outlet 35 is reached. 4 Airscoop ii) is provided witha. cylindrical outlet 39 that merges into a small covered rectangularcollecting chamber 40. The entrance to chamber 49 is an open flatbottomed channel or trough formed by bottom 4! and parallel sides orflanges 42 with upper edges diverging from the inner end of bottom 4! tothe top of collecting chamber 40. Thus is formed an open channel 43partially enclosing the teeth of the flywheel as they pass the airscoopfor receiving the air from the flywheel teeth. Attaching extensions 44provide means for securin the airscoop to the flywheel casing. Conduit12 connects outlet 39 with inlet 34 of the aspirator.

The device is assembled on an engine by cutting a hole in the bottom ofthe flywheel casing adjacent the teeth of the flywheel and securing theairscoop as shown in Fig. 2. If no ventilating air inlet is provided inthis casing then one is made preferably near or at the top. An outlet.hole is cut in the crankcase above the oil level and any other breatheroutlet located higher is plugged up. The baiile assembly is secured tothis outlet as above described. The conduits connecting the baffle withthe separator, the separator with the aspirator and the airscoop withthe aspirator are then positioned and the assembly is ready foroperation.

In operation the rotation of the flywheel teeth creates a blower actionto drive air into the airscoop. It has been found that the flanged inletchannel 13 partially enclosing the flywheel teeth and the enclosedcollecting chamber 49 located adjacent the point the teeth leave channel43 results in highly efiicient operation for the air moved by theflywheel teeth is thus collected and directed out of the airscoop with aminimum of loss. The bafile construction 5 makes it diflicult forlubricating oil to be drawn or forced into the scavenger assembly andthe separator l prevents oil thathas entered the scavenger from beingdischarged with the undesirable fumes, gases and vapors and permits itsreturn to the crankcase. It is clear that the lighter gases and fumeswill readily be drawn through the separator outlet while .the heavieroils will be held in the separator chamber and will return by gravity tothe crankcase.

The novel aspirator 9 provides an additional restriction of the pressurefrom the airscoop seeking the outlet of the system, at a point adjacentthe lower end of the inlet tube 32. The restriction is released withinthe aspirator, as shown and described, and this assembly has been foundhighly eflicient in creating the desirable suction to withdraw theundesirable vapors from the crankcase.

It is obvious that in some cases the scavenger may be advantageouslyinstalled directly to the outlet breather of the engine without cuttinga new outlet in the crankcase casing and without using the baflieassembly. Also it may be desirable to omit the separator fromv theinstallation in certain instances where it is desired to minimize thecost of equipment or where the crankcase. outlet is so positioned thatthere is little likelihood of oil entering. the scavenger. However, theinclusion of both bafiie and separator. in the installation will assureeflicient crankcase scavenging without loss. of desired lubricatingoils.

I claim:

1. In a crankcase scavenger assembly for internal combustion engineswherein the teethof the flywheel are utilized as the blower means, theimprovement which comprises an airscoop having flanges at each side toprovide a troughli'ke'inlet wherein the teeth of the flywheel will bepositioned to move air into the airscoop when in operation.

2. In a crankcase scavenger assembly for internal combustion engineswherein the teeth of the flywheel are utilized as the blower means, theimprovement which comprises an airscoop having a collecting chamber anda troughlike inlet with parallel sides leading thereto and means forsecuring the airscoop adjacent the flywheel with a part of the teeththereof extending. within the troughlike inlet.

3. In a crankcase scavenger assembly for in-- ternal combustion engineswherein an airscoop is positioned on the flywheel casing to. utilize theflywheel teeth as the blower means; the improve ment which comprises. anairscoop having a troughlike entrance formed by flanged sidesex- 7tending upwardly from the bottom and means on theairscoop for securingit to the. flywheel casing with said sides extending within the casingto position the teeth. of the flywheel within the troughlike entrance.

CLARK C. RANDALL.

REFERENCES CITED The following references. arev of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,723,412 'DeWaters 'Aug. 6',1929 1,788,897 Taylor Jan. 13, 1931 1,795,927 Daubner Mar. 10, 19311,828,085 Syrovy-et al Oct. 20, 1931 7 2,305,186 Muenk Dec- 15, 19422,406,103 Randall "an... Aug. 20, 1946-

